Elbow



FIG. 1 is a top, front, and right side perspective view of a first embodiment of an elbow embodying our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7. 

CLAIM The ornamental design for an elbow, as shown and described. 